Prediction of uniformity of a wafer

Abstract

A method of monitoring uniformity of a wafer is provided. A wafer parameter is selected. Manufacturing data is collected. The manufacturing data includes measurements of the selected wafer parameter. An average offset profile of the wafer parameter for a first and second wafer is determined using the manufacturing data. The first and second wafer are associated with a product type and were processed by a processing tool. An offset profile for a third wafer is predicted for a wafer using the average offset profile. The third wafer is associated with the product type and was processed by the processing tool.

1. A method of monitoring uniformity of a wafer comprising:
 selecting a wafer parameter; 
 collecting manufacturing data including a measurement of the wafer parameter for a first wafer and a second wafer, wherein the first wafer and the second wafer are associated with a product type and were processed by a processing tool; 
 determining an average offset profile of the wafer parameter for the first wafer and the second wafer using the collected manufacturing data wherein the average offset profile includes an average offset from a mean value of the selected wafer parameter at a plurality of locations on the first wafer and the second wafer; and 
 predicting an offset profile for a third wafer associated with the product type and processed by the processing tool using the determined average offset profile, wherein a computer comprising a recordable medium on which is stored instructions for at least one routine performs the determining the average offset profile and the predicting the offset profile. 
 
   
   
     2. The method of  claim 1  wherein the processing tool is correlative to the wafer parameter. 
   
   
     3. The method of  claim 1  wherein the wafer parameter is a dimension of a feature. 
   
   
     4. The method of  claim 1  wherein the processing tool is a first chamber of a fabrication tool. 
   
   
     5. The method of  claim 1  further comprising:
 using the predicted offset profile to determine subsequent processing of the third wafer. 
 
   
   
     6. The method of  claim 1  further comprising:
 using the predicted offset profile to monitor a processing tool. 
 
   
   
     7. A method of semiconductor wafer processing comprising:
 providing a first wafer associated with a product type and processed in a processing chamber; 
 determining a mean value of a wafer parameter for the first wafer; 
 determining an average offset profile of the wafer parameter for a second wafer and a third wafer associated with the product type and processed in the processing chamber wherein the average offset profile includes an average offset from a mean value of the wafer parameter at a plurality of locations on the second wafer and the third wafer, and 
 predicting a value of the wafer parameter at a location on the first wafer using the average offset profile and the mean value of the parameter for the first wafer; and 
 using the predicted value of the wafer parameter to determine a process parameter for a fabrication process step; and 
 performing said fabrication process step. 
 
   
   
     8. The method of  claim 7  wherein the wafer parameter comprises a thickness of a layer. 
   
   
     9. The method of  claim 8  wherein the layer comprises a dielectric layer. 
   
   
     10. The method of  claim 7  wherein the processing chamber comprises a CVD chamber. 
   
   
     11. The method of  claim 7  wherein the average offset profile is determined using at least one of an EWMA and a moving average. 
   
   
     12. The method of  claim 7  wherein the determining the mean value of the wafer parameter includes predicting the mean value of the wafer parameter. 
   
   
     13. The method of  claim 7  further comprising:
 predicting values for the wafer parameter at a plurality of locations on the first wafer. 
 
   
   
     14. The method of  claim 7  wherein the first wafer is included in a lot of wafers, and wherein the lot of wafers includes a fourth wafer having the wafer parameter measured for at least one location. 
   
   
     15. A computer recordable medium on stored instructions when executed perform at least one routine operable to:
 receive manufacturing data; 
 determine an average offset profile for a wafer parameter using the manufacturing data, wherein the average offset profile includes a first average value the wafer parameter is offset from a mean value at a first location of a wafer and a second average value the wafer parameter is offset from the mean value at a second location of a wafer; and 
 predict the wafer parameter for a first wafer of a product type and processed in a processing chamber based on the determined average offset profile. 
 
   
   
     16. The computer of  claim 15  further operable to:
 select a process parameter from the received manufacturing data, wherein the selected process parameter is correlative to the wafer parameter. 
 
   
   
     17. The computer of  claim 15  wherein the determining the average offset profile includes determining an offset profile for a second wafer and determining an offset profile for a third wafer, wherein the second wafer and the third wafer are associated with the product type and processed in the processing chamber. 
   
   
     18. The method of  claim 1 , further comprising:
 sending the predicted offset profile for the third wafer to a fabrication tool; 
 determining a process parameter for the fabrication tool; and 
 performing a fabrication process step using the fabrication tool and the determined process parameter.